The Society of St. Pius X (SSPX) was founded by
Archbishop Lefebvre, a retired missionary bishop who served in Africa, in
order to perpetuate the Tridentine Mass. He did not reject Vatican II, or
even the reform of the Mass (he voted for the Council document that called
for it), but he did reject the current rites, promulgated in 1969, though
he did not argue they was invalid. He started a seminary in Ecône,
Switzerland, to train priests, which he then ordained. As a bishop who was
not an Ordinary (bishop of a diocese) at the time, he was not permitted to
ordain priests. Pope Paul VI suspended his priestly faculties, and those
he ordained, for this defiance of Church law. Time going on the movement
rejected ecumenism and the statements of the Council on religious liberty,
as contrary to Tradition.

Within the Traditionalist movement, which is
certainly dominated by the Society, other branches developed. For example,
the SSPX uses the 1962 Missal, which includes changes made by John XXIII.
Some in the movement reject any changes, and thus will use only the Missal
from Pius XII's time. Others argue that the See of Peter is vacant since
Pius XII (sedevacantists). Others have elected their own popes (there
were, at last count, at least 3 antipopes). And so the fracturing natural
to schismatics has its way.

In 1989, Archbishop Lefebvre, fearing that he would
soon die and leave no one to ordain priests for the SSPX, sought an
agreement with the Holy See for the lawful continuation of the Society.
After first reaching one, with Cardinal Ratzinger acting for the Pope,
Lefebvre reversed himself, and in an act which was <i>ipso
facto</i> schismatic ordained 4 bishops without a papal mandate and
incurred an automatic excommunication, confirmed a few days later by Decree
of the Holy See.

In these circumstances, some number of seminarians at
Ecône and priests of the SSPX, not wanted to go into schism, sought an
agreement with Rome, which concluded with the founding of the Priestly
(Sacerdotal) Fraternity of St. Peter (FSSP). This immediate erection of
the Fraternity by the Holy See, without all the preliminaries of time and formality
usually required of time, was a tremendous charity by the Pope toward the
former members of the SSPX, who have returned it with loyalty and
faithfulness, as well as the devotion to the Tridentine rites which is
their proper charism. (The Fraternity, therefore, celebrates the Mass
according to the Missal of 1962.) On the other hand, the SSPX has gotten
more strident over time, harboring sedevacantists and others with
positions more extreme than Archbishop Lefebvre would have tolerated.